Light in a ball

[Mellinia]

Picture a sphere, the outer and inner shell are made of absolute reflective materials, with a fiber optic wire at one point on the sphere. It has a "stopcock" to stop the transmit of light into the sphere. If I send in light signals into the mirror-walled sphere through the wire, and close the stop cock after one minute, would:

1)The light signal continue reflecting in the sphere forever, provided that there is no outside influence, and the reflective material has absolute reflectivity, no light is absorbed?

2)The light signal be the same if I let it out through the fiber optic again?

3)I be able to store light?

[swansont]

In principle the light would bounce around for a long time, getting slightly redder with each bounce to conserve momentum and energy, until you reached thermal equilibrium. (At some point the sphere would not be able to support the wavelength shift anymore, which is an interesting situation; I suspect you'd just have a standing wave at that point. otherwise you would get a broadening of the spectrum due to thermal motion of the surface)

 

Even with no change in wavelength, the light would not easily couple back into the fiber, except under certain circumstances. Light leaving the fiber diffracts, and would not automatically bounce back into the fiber. Eventually it would; the signal would tend to decrease in intensity and it would take a longer time to get the light out.

 

Yes, you can use this concept to store light for a small amount of time. In practical terms though this is still a short amount of time, unless the ball is huge.

[Klaynos]

Sounds similar to an integrating sphere....

 

http://en.wikipedia.org/wiki/Integrating_sphere

[alpha2cen]

Light's direct motion property inhibits that instrument work well.

If light's direct motion is interfered with some materials, it's energy is reduced.

And light transfer medium, without vacuum, reduces light's energy, too.

[Mellinia]

So...basically it would work, in a partial vacuum and with absolute reflective materials. Can light direction be altered by means of magnetic forces?

[alpha2cen]

So...basically it would work, in a partial vacuum and with absolute reflective materials. Can light direction be altered by means of magnetic forces?

 

Generally, light direction can not be controlled by magnetic force. But I do not know very very huge magnetic force, i.e., neutron star control the light direction or not?

[Mellinia]

Light is a electromagnetic wave? How do you control the direction of radio waves?

[alpha2cen]

Light is a electromagnetic wave? How do you control the direction of radio waves?

 

How about look this site?

see from #14

http://www.scienceforums.net/topic/53664-light-vacuum-travel/

[Mellinia]

Thanks! Light is a very complicated substance.

 

 

 

In principle the light would bounce around for a long time, getting slightly redder with each bounce to conserve momentum and energy, until you reached thermal equilibrium. (At some point the sphere would not be able to support the wavelength shift anymore, which is an interesting situation; I suspect you'd just have a standing wave at that point. otherwise you would get a broadening of the spectrum due to thermal motion of the surface)

 

Even with no change in wavelength, the light would not easily couple back into the fiber, except under certain circumstances. Light leaving the fiber diffracts, and would not automatically bounce back into the fiber. Eventually it would; the signal would tend to decrease in intensity and it would take a longer time to get the light out.

 

Yes, you can use this concept to store light for a small amount of time. In practical terms though this is still a short amount of time, unless the ball is huge.

 

What is a standing wave and what properties does it have?

[swansont]

Light's direct motion property inhibits that instrument work well.

If light's direct motion is interfered with some materials, it's energy is reduced.

And light transfer medium, without vacuum, reduces light's energy, too.

 

No, the light's energy is not affected by the medium. Energy is conserved. The wavelength is affected by having an index ≠ 1, but the frequency and energy are unaffected by this.

 

 

What is a standing wave and what properties does it have?

 

http://en.wikipedia.org/wiki/Standing_wave

[alpha2cen]

No, the light's energy is not affected by the medium. Energy is conserved. The wavelength is affected by having an index ≠ 1, but the frequency and energy are unaffected by this.

 

 

The medium molecules can absorb light energy, i.e., absorption phenomena.

There is no molecules which perfectly passes light without any intensity decrease.

light energy------>light energy + heat energy.

Energy conservation law is correct.

Do light bending and light energy reduction have no correlation?

[swansont]

The medium molecules can absorb light energy, i.e., absorption phenomena.

There is no molecules which perfectly passes light without any intensity decrease.

light energy------>light energy + heat energy.

Energy conservation law is correct.

Do light bending and light energy reduction have no correlation?

 

Molecules absorb individual photons, but the ones not absorbed have the same energy.